The Sunshine State is poised to be the second largest solar energy producer in the country, thanks to three new Florida Power & Light plants that use glimmering rows of solar panels or mirrors to convert sunlight to power.

FPL kicked off operations at a solar plant in DeSoto County in October with great fanfare, including an appearance by President Barack Obama. The DeSoto plant and two others in Martin and Brevard counties scheduled to open this year will generate 110 megawatts of energy, enough to power 35,000 homes.

But some consumer advocates and utility critics are raising concerns about the high cost of solar.

Several proposals that legislators are considering would allow utilities to pass on the costs of such projects to consumers without traditional state oversight.

"We have got to look at all energy solutions," said Sen. Mike Haridopolos, a Melbourne Republican in line to be the next Senate president. "The ratepayers need to know exactly what the costs would be. … In a very weak economy, asking consumers to pay three or four times more may be untenable.

FPL's solar plants were built under a provision in a 2008 law that allowed utilities to pass the cost of plants generating up to 110 megawatts of clean energy — without regulators deciding whether the extra energy is needed — for projects proposed by July 2009. FPL officials have said that kind of a provision is needed for it move forward with other solar projects.

Legislators have introduced half a dozen alternative-energy and energy efficiency bills that aim to speed up such initiatives. Several bills proposed would require utilities to pay renewable energy producers the same rate they get for alternative energy; have 20 percent of their energy come from renewable resources by 2022; and levy a 25 cent monthly fee from customers for state rebates for people who use energy saving products.

Another key bill would allow utilities to pass to customers the cost of renewable power plants generating up to 700 megawatts of energy in the next few years.

The House version of the bill, proposed by Rep. Trudi Williams, R-Fort Myers, would also allow utilities to earn a higher profit on shareholders' investment for the plants than has been approved by regulators for other power facilities. That would allow FPL an 11.5 percent profit, which is paid for by utility customers.

FPL officials said they have not taken formal positions on bills but legislators consulted with utility executives, including FPL Vice President and Chief Development Officer Eric Silagy, on the measures. "As the state's largest solar energy producer, we support legislation that encourages further investment in the expansion of renewable energy production and solar technologies in Florida," FPL spokesman Mayco Villafana said.

Like the provision in the 2008 law, the legislation this year does not limit the cost to customers and does not require the utility to explore options that might produce more renewable energy at a cheaper cost. FPL's three solar projects cost $659 million – adding up to about 25 cents per month for a typical customer for 25 years – but the plants and another project that has been shelved would only bump up the utility's renewable energy capacity from about 1.4 percent in 2007 to about 1.9 percent.

A 2009 study by Navigant Consulting commissioned by the state regulators found the costs for solar power are significantly higher than other renewable energy sources. The study estimated solar power costs about $7,100 per potential kilowatt of energy but would drop to $4,300 by 2020. By comparison, energy generated by solid biomass plants costs $4,000 per kilowatt and wind power $2,470. At the same time, power generated by household solar water heating units costs $1,700 per kilowatt. The estimates don't factor in that some renewable energy generators can't run all the time because they're dependent on good weather.

Large renewable energy plants – built by utilities or others – leverage their size to save money while smaller systems in homes or businesses don't lose as much energy because they don't have to travel through hundreds of miles of power lines.

Michael Dobson, president of Florida Energy Producers – a group of about 40 renewable energy producers, project developers and economic development groups – said the Williams bill is appealing to his group and lawmakers because job creation is critical. But he said it would "allow for a unique return on investment that I'm not sure is the best thing for consumers."

"Let's just call it what it is: it's a utility bill," he said. "It does encourage more renewable energy, but the bad thing is, it still maintains the status quo in that it passes additional costs to consumers."

Dobson told the House utilities committee last week that utilities and independent renewable energy producers should be allowed "to fight it out" for business instead of any group receiving advantages.

Sen. Mike Bennett, R-Bradenton, who proposed the Senate's version of the bill, said it would boost the state's economy and jump-start its renewable energy industry.

"We've got to find ways to encourage renewable energy [by] either subsidizing them or coming up with a financing program that will allow people to put renewable energy products in their house," he said.